While giving anal sex to a girl in doggy style position, you kick out her arms (don't break them) so she falls on her face, she'd then put her arms around her face and you'd push around the room like a snowplow.

While giving it to her in the ass, I took out her arms and gave her a snowplow!

the REAL definition is this: a man is giving it to a girl from behind. he then pulls her up by the legs and knocks her arms out from under her. He then proceeds to drive her across the carpet on her face like a snow plow.

When a couple is performing sex in the doggy style possition, the man yells "Snow Plow!" Then proceeds to reach forward and pull the womans arms out form under her. The woman then falls face first, resulting in the snow plow appearance.

Kati from work needed a good pounding so I gave her the snow plow, to keep it interesting.